In wireless transceivers, down converters transform a radio frequency (RF) signal into a baseband signal centered at the zero frequency. Similarly, up converters transform a baseband signal into an RF signal. Down conversion and up conversion have traditionally been performed in the analog domain. However, the wireless transceivers of the next generation perform down conversion and/or up conversion in the digital domain. For example, a receiver may employ RF sampling, in which the RF signal is directly sampled with a high speed, high performance analog-to-digital converter (ADC) (e.g., a 14 bit, 3 giga-sample-per-second ADC). The use of RF sampling allows such receivers to employ digital down-converters that avoid mixers in the RF/analog domain. In a digital down-converter, mixing is implemented using digital multiplication circuitry.